Post-genomics of microsporidia, with emphasis on a model of minimal eukaryotic proteome: a review

Abstract

Abstract. The genome sequence of the microsporidian parasite Encephalitozoon cuniculi Levaditi, Nicolau et Schoen, 1923 contains about 2,000 genes that are representative of a non-redundant potential proteome composed of 1,909 protein chains. The purpose of this review is to relate some advances in the characterisation of this proteome through bioinformatics and experimental approaches. The reduced diversity of the set of E. cuniculi proteins is perceptible in all the compilations of predicted domains, orthologs, families and superfamilies, available in several public databases. The phyletic patterns of orthologs for seven eukaryotic organisms support an extensive gene loss in the fungal clade, with additional deletions in E. cuniculi. Most microsporidial orthologs are the smallest ones among eukaryotes, justifying an interest in the use of these compacted proteins to better discriminate between essential and non-essential regions. The three components of the E. cuniculi mRNA capping apparatus have been especially well characterized and the three-dimensional structure of the cap methyltransferase has been elucidated following the crystallisation of the microsporidial enzyme Ecm1. So far, our mass spectrometry-based analyses of the E. cuniculi spore proteome has led to the identification of about 170 proteins, one-quarter of these having no clearly predicted function. Immunocytochemical studies are in progress to determine the subcellular localisation of microsporidia-specific proteins. Posttranslational modifications such as phosphorylation and glycosylation are expected to be soon explored.

Proteomics in evolutionary ecology: linking the genotype with the phenotype

“…1999; Zivy & de Vienne 2000; Thiellement et al. 2002; Edwards & Batley 2004), microorganisms (Texier et al. 2005; Thomas et al.…”

Identification of a New Spore Wall Protein from Encephalitozoon cuniculi

“…With the publication of the E. cuniculi genome, this has permitted us and other investigators to initiate proteomic studies on the composition of these structures (36). PTP1 has been identified to be modified by posttranslational glycosylation involving mannosylation (45), and some of the components of the spore wall appear to be similarly modified (L. M. Weiss, unpublished observation).…”

“…2, highlighted serine residue in the basic KS domain). The presence of such GPI-anchored proteins has not been experimentally determined with microsporidia, but enzymes such as GlcNAc-P i that are associated with GPI anchor formation are clearly present in the E. cuniculi genome (21,36).…”

Proteomics and Host—Pathogen Interactions

“…By contrast, this represents one major limitation to characterize hostÀpathogen interactions, but also a challenging perspective for proteomics technology. This is why retrospectively proteomics studies were mainly conducted to evidence pathogenic virulence and pathogenicity factors (Ouellette et al, 2003;Texier et al, 2005;Sims and Hyde, 2006;Van Hellemond et al, 2007;Liu et al, 2008a,b;Bird and Opperman, 2009;Jagusztyn-Krynicka et al, 2009;Premsler et al, 2009;Weiss et al, 2009;Steuart, 2010;Bhavsar et al, 2010;Holzmuller et al, 2010).…”